The “Golden State Killer” was meticulous at his crime scenes over the course of a decade and in several cities, leaving scant evidence for police. There were no fingerprints. Few saw his face. And what he did leave — his DNA — was, at the time, not useful to police.
Four decades later, with far better DNA technology and widespread use of it, that genetic material became critical to possibly solving one of the most vexing serial murder sprees in U.S. history. Authorities said they were able to link their suspect to the string of crimes by using a genealogy service to trace the genetic material to one man they believe killed at least a dozen people: Joseph James DeAngelo.